Drawer apparatus for radio frequency heating and defrosting

Abstract

A radio-frequency (RF) heating system may include a removable drawer, which may be inserted under a fixed shelf of the RF heating system to form an enclosed cavity. The drawer may include conductive channels or side rails that may interface with the shelf of the defrosting system in order to electrically couple the drawer to the RF heating system. The drawer may include an electrode that is electrically coupled to ground or to a RF signal source when the drawer is inserted beneath the shelf. The shelf may include selectable electrodes of varying sizes. The RF heating system may use identification circuitry to recognize the type of drawer that has been inserted beneath the shelf. RF energy may be applied to the electrode of the drawer or the shelf to heat a load in the enclosed cavity.

The invention claimed is: 
     
       1. A system comprising:
 a radio frequency (RF) signal source configured to produce an RF signal; 
 a first structure comprising a shelf and including:
 a first electrode, wherein the first electrode is configured to electrically couple to the RF signal source; and 
 a second electrode adjacent to the first electrode, wherein the second electrode is configured to electrically couple to the RF signal source; 
 
 a second structure comprising a platform that forms a portion of a removable drawer, wherein the first structure and the second structure are configured to be physically engaged together in a non-permanent manner to create a cavity between the first structure and the second structure when the second structure is inserted under the first structure, the second structure comprising:
 a third electrode that at least partially vertically overlaps at least one of the first electrode and the second electrode when the second structure is physically engaged with the first structure, and 
 a first conductive feature that is permanently coupled to the second structure, wherein the first conductive feature is permanently electrically coupled to the third electrode, wherein the platform includes an identifier coupled to the platform that identifies at least one of a size and a shape of the third electrode; 
 
 a second conductive feature that is configured to physically and electrically connect to the first conductive feature when the second structure is fully physically engaged with the first structure; and 
 recognition circuitry configured to:
 detect the identifier; and 
 cause one of the first electrode and the second electrode to be electrically coupled to the RF signal source and the other of the first electrode and the second electrode to be disconnected from the RF signal source based on the identifier. 
 
 
     
     
       2. The system of  claim 1 , wherein the removable drawer is formed entirely from conductive material. 
     
     
       3. The system of  claim 1 , wherein the removable drawer further comprises:
 a side rail to which the first conductive feature is connected; 
 dielectric material on which or in which the third electrode is formed; and 
 one or more conductive traces formed in or on the dielectric material that electrically connect the third electrode to the first conductive feature. 
 
     
     
       4. The system of  claim 3 , wherein the first conductive feature is integrally formed with the side rail. 
     
     
       5. The system of  claim 3 , further comprising:
 a voltage reference electrically coupled to the second conductive feature; and 
 a channel into which the side rail is insertable, wherein the first and second conductive features connect when the side rail is fully inserted into the channel to provide an electrical path between the third electrode and the voltage reference. 
 
     
     
       6. The system of  claim 5 , wherein the second conductive feature is positioned at a top interior surface of the channel, and wherein the channel comprises:
 a nub formed on a portion of a bottom interior surface of the channel, wherein the first conductive feature of the side rail is held in electrical contact with the second conductive feature at the top interior surface of the channel by the nub when the side rail is fully inserted into the channel. 
 
     
     
       7. The system of  claim 6 , wherein the nub is formed from a material selected from the group consisting of nylon and polytetrafluoroethylene. 
     
     
       8. The system of  claim 6 , wherein the side rail comprises:
 a first portion that extends along a first axis and that includes a distal portion that is in contact with the nub and the top interior surface of the channel when the side rail is fully inserted into the channel, wherein the top interior surface of the channel is planar; 
 a second portion that extends along a second axis parallel to the first axis and that is in contact with an additional portion of the bottom interior surface of the channel that is different from the portion of the bottom interior surface of the channel on which the nub is formed when the side rail is fully inserted into the channel, wherein the bottom interior surface of the channel is planar; and 
 a third portion that extends along a third axis that intersects the first and second axes and that connects the first portion to the second portion, wherein an entire top surface of the first portion is in contact with the top interior surface of the channel and the first portion is parallel to the top interior surface of the channel when the side rail is fully inserted into the channel and the distal portion of the first portion is in contact with the nub and the bottom surface of the second portion is in contact with the additional portion of the bottom interior surface.